The present invention relates generally to operations performed in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a method of gravel packing a multilateral well.
Wells which have intersecting wellbores (“multilateral wells”) generally require the wellbore intersections to be sealed. Many proposals have been made for accomplishing this difficult task of sealing wellbore intersections. Some of these have been quite successful and enjoy widespread acceptance in the industry.
However, special problems are encountered when a branch wellbore and a parent wellbore intersect at or relatively near a horizontal inclination and a gravel packing operation is to be performed in the branch wellbore. In the past, this was accomplished by setting a gravel pack packer in the parent wellbore with a well screen positioned in the branch wellbore. A gravel slurry was pumped outwardly through a crossover or other discharge device in the parent wellbore below the packer, and flowed into the branch wellbore.
Unfortunately, this procedure typically results in gravel being deposited on the low sides of the parent and branch wellbores at the intersection. This gravel at the intersection is hard to remove, and it interferes with achieving a seal between the parent and branch wellbores. Of course, this situation is most troublesome when the branch wellbore is completed open hole and, thus, there is no liner available in the branch wellbore to seal against at the wellbore intersection.
Therefore, it may be seen that it would be desirable to provide improved methods of gravel packing a branch wellbore.